Several recent arxiv articles like http://arxiv.org/abs/1409.6290/ reviewing the pbr theorem http://arxiv.org/abs/1111.3328/ got me thinking about this again with respect to straightforward two-slit interference, which I'd thought simply and unambiguously resolved the issue in favor of "it's real". And that resolution goes back to (and likely before) Feynman's general audience lectures http://en.wikipedia.org/wiki/The_Character_of_Physical_Law https://www.amazon.com/The-Character-Physical-Modern-Library/dp/0679601279 You can perform a two-slit electron interference experiment, and slowly reduce the luminosity/intensity of the source until it's so low that you're virtually guaranteed that only one electron at a time passes through the slits. And then accumulated counts at the scintillation screen still exhibit interference. So doesn't that simply mean the wavefunction/quantum_state is ontologically "real"? If it just represented epistemic ensemble statistics, there wouldn't be any self-interference from a low-luminosity source. That argument seems pretty obvious, so I guess it must be flawed, or I'd imagine it would be widely used. So what's wrong with it?